<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.11/vue.min.js"></script>
</head>

<body>
    <div id="app">
        {{msg}}
        <div v-for="item in list">
            <div v-show="item.age > 20" :class="['active','add','more',{'another': item.age < 30}]" :style="styleMsg">
                {{item.name}}
            </div>
        </div>
    </div>
    <script>
        var app = new Vue({
            el: '#app',
            data: {
                msg: 'Hello Vue!',
                styleMsg: {
                    color: 'red',
                    textShadow: '0 0 5px green'
                },
                list: [{
                    name: '小林',
                    age: 18
                }, {
                    name: '小蚂蚁',
                    age: 24
                }]
            }
        })
    </script>

</body>

</html>